Gas chromatographic/mass spectrometric analysis of on-line pyrolysis–silylation products of monosaccharides

Classification of polysaccharides may be achieved on the basis of the monosaccharidic composition after cleavage of glycosidic bonds. Pyrolysis is a useful method to obtain polysaccharide decomposition and generally pyrolysis products can be identified by the use of gas chromatography/mass spectrometry. This paper describes an on-line silylation pyrolysis approach and compares the efficiency of two derivatization reagents, hexamethyldisilazane (HMDS) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA), used alone and in combination with trimethylchlorosilane (TMCS) as a catalyst. Some characteristic trimethylsilyl derivatives of monosaccharides have been identified on the basis of their mass spectra. The detected products include trimethylsilyl derivatives of anhydrosugars, cyclopentenones, furancarboxyaldehydes and, at the best silylating conditions, pertrimethylsilylated monosaccharides. The optimization of the derivatization process is under study, as well as the possibility to extend the use of this approach to unknown polysaccharidic samples, with particular attention to cultural heritage materials.